1. Field of the Invention
The present invention relates to an apparatus, a method, and a program for performing audio signal processing on an audio signal from a sound source localized at a given angle.
2. Description of the Related Art
Audio signals representing contents recorded on recording media, such as a compact disc (CD) and a digital versatile disc (DVD), and contents, such as television (TV) broadcast programs, contain audio signals from various kinds of sound sources. For example, music contents contain audio signals from sound sources, such as singing voices and sounds of musical instruments. In addition, TV broadcast program contents contain audio signals from sound sources, such as voices of the cast, sound effects, laughter, and clapping sounds.
Although these audio signals from sound sources are often recorded using different microphones during recording, even in that case, the audio signals are eventually downmixed to a predetermined number of channels, such as 2 channels (2 ch) and 5.1 channels (5.1 ch). At this time, the audio signals are adjusted by performing mixing or other processing so that each sound source is localized at the corresponding angle. Herein, the term “channel” may be abbreviated as “ch” as shown in the above with brackets.
Japanese Unexamined Patent Application Publication Nos. 2006-121152, 2006-080708, 2006-014220 describe techniques that allow separation of mixed audio signals from a plurality of sound sources and utilization of the separated signals.